FREE 

RAILROAD  VALLEY 
COMPANY 


University  of  California  •  Berkeley 


Railroad  Valley  Company 


POTASH 


REPORT   OF 

E.  E-  FREE 


A/. 


Railroad  Valley  Company 

ORGANIZED  UNDER  LAWS  OF 
STATE  OF  NEVADA 

Capital   $1,000,000— One    Million   Shares— $1.00  Each 
Fully  paid  and  non-assessable 

MAIN  OFFICE 
308-9    State    Bank    Building,    Tonopah,    Nevada 


DIRECTORS 

CLYDE  A.  HELLER,  President  Tonopah-Belmont  Dev.  Co.,  Bullit  B'ld.,  Philadelphia 

MAX    J.    BRANDENSTEIN,  M.  J.  Branden.tcin  Co.,  San  Francisco 

JAS.  T.  DONAHUE,  Sec'ty  National  Ice  Co.,  San  Franciico 

EUGENE  HOWELL,  Tonapah  Banking  Corp.,  Tonopah 

W.  W.  CHARLES,  Tonopah  Mining  Co.,  of  Nevada,  Tonopah 

HUGH  H.  BROWN,  Attorney,  Tonopah 

VICTOR  BARNDT,  Tonopah 

OFFICERS 

VICTOR  BARNDT,  President 
HUGH  H.   BROWN,  Vice-President 

D.  H.  WALKER,  Treasurer 

E.  A.  KEENAN,  Secretary 

TONOPAH  BANKING  CORP.,  Registrar  and  Depository 


YUAHUI 


Railroad  Valley  Land  &  Water  Co. 

ORGANIZED  UNDER  THE  LAWS  OF 
THE  STATE  OF  NEVADA 

Capital  $500,000—500,000  Shares— $1.00  Each 

MAIN  OFFICE 
308-9  State  Bank  B'ldg.,  Tonopah,  Nevada 

OFFICERS    AND     DIRECTORS 

WARREN    V.    RICHARDSON,    President    and    Director 
HUGH    H.    BROWN.    Vice-President    and    Director 

D.  H.    WALKER,    Treasurer    and    Director 

E.  A.    KEENAN,    Secretary 
E.   L.   FLETCHER.   Dir«ctor 
VICTOR  BARNDT,   Director 


INTRODUCTION. 

The  main  object  of  the  Railroad  Valley  Company  is  to  dis- 
cover valuable  potash  salt  deposits.  We  are  drilling  in  the  Rail- 
road Valley  (Nye  County,  Nevada)  basin  for  a  potash  salt  or 
brine  deposit  supposed  to  exist  in  the  lowest  depression  in  the 
bottom  of  a  former  lake,  now  buried.  The  present  well  is  1200 
feet  deep  and  results  to  date  are  inconclusive  but  strengthen  the 
general  theory.  It  is  possible  that  three  wells  may  be  required 
to  locate  the  potash  body. 

We  have  also  started  a  comprehensive  research  in  other 
localities  of  the  Great  Basin,  where  geological  and  former  lake 
conditions  are  favorable.  This  research  is  under  charge  of  Mr. 
E.  E.  Free,  formerly  of  U.  S.  Bureau  of  Soils  in  charge  of  Desert 
Basin  Potash  Research  of  the  United  States  Government. 

Incidental  to  its  main  object  the  Railroad  Valley  Company 
will  develop  any  agricultural  possibilities  indicated  by  its  potash 
explorations.  Any  basin  that  indicates  buried  potash  bodies  is 
almost  sure  to  be  an  artesian  water  basin  as  well,  as  both  possi- 
bilities depend  upon  similar  topographic  conditions.  These 
basins  usually  contain  large  areas  of  fertile  land,  which  artesian 
water  will  make  very  valuable. 

In  Railroad  Valley  the  drilling  to  date  lias  already  estab- 
lished an  important  agricultural  possibility.  The  Railroad  Val- 
ley Land  and  Water  Company,  a  subsidiary  corporation  oper- 
ated in  the  interests  of  the  Railroad  Valley  Company,  has  ac- 
quired this  artesian  basin,  and  in  the  judgment  of  experts  should 
in  time  develop  a  land  value  great  enough  to  make  the  shares  of 
the  Railroad  Valley  Company  worth  par. 

The  following  discussion  by  Mr.  Free  upon  the  subject  of 
potash  and  the  possibility  of  its  discovery  under  the  "Dry  Lake 
Theory,'7  and  interpretation  of  the  development  record  in  Rail- 
road Valley,  is  published  to  meet  requests  of  stockholders  and 
other  interested  parties  for  details  of  the  scientific  evidence  upon 
which  we  base  our  undertakings. 

RAILROAD  VALLEY  COMPANY. 

August  22,  1912. 


Potash  and  the  Dry  Lake  Theory. 

POTASH,  USES  AND  SOURCES. 

Outside  of  museums  the  metal  potassium  is  known  only 
through  its  soluble  compounds  or  "salts,"  for  any  or  all  of  which 
the  term  potash  is  the  common  designation.  The  salts  of  potas- 
sium have  many  and  varied  uses,  by  far  the  greatest  of  which  is 
in  the  manufacture  of  artificial  or  "commercial"  fertilizers. 
Such  fertilizers  are  of  various  types,  but  the  so-called  "complete 
fertilizer"  contains  three  essential  ingredients — potash,  phos- 
phate and  nitrogen.  The  use  of  such  fertilizers — and  hence  the 
use  of  potash — is  very  rapidly  on  the  increase,  not  so  much  be- 
cause soils  are  "wearing  out"  as  because  the  increasing  scarcity 
of  land  is  making  necessary  a  greater  soil  productivity  and  more 
and  more  intensive  forms  of  agriculture.  In  the  United  States 
this  intensification  of  agriculture  has  scarcely  more  than  begun, 
but  it  must  both  persist  and  increase  if  we  are  to  feed  our  rapidly 
growing  population.  And  intensive  agriculture  means  fertiliza- 
tion, regardless  of  the  richness  or  poorness  of  the  soil.  Indeed, 
it  is  the  universal  experience  that  fertilizers  yield  the  greatest 
increase  and  are  most  worth  while  not  on  the  poorest  soils  but 
on  the  best.  Artificial  fertilization  is  not  so  much  a  remedy  for 
poor  or  mistreated  soils  as  it  is  a  necessary  and  universal  accom- 
paniment to  the  cultivation  of  all  soils.  There  is  every  reason 
to  expect  a  continued  and  very  rapid  increase  in  the  use  of  fer- 
tilizers and,  since  potash  is  nearly  always  an  essential  constitu- 
ent, this  means  a  large  and  increasing  use  of  potash. 

A  half  century  ago,  when  potash  was  made  entirely  from 
wood  ashes,  there  was  a  flourishing  potash  industry  in  the 
United  States,  but  under  the  competition  of  the  cheaper  German 
salts  this  industry  has  declined  almost  to  nothing,  and  prac- 
tically all  the  potash  now  consumed  is  imported.  The  volume 
of  these  imports  is  indicated  in  the  following  table : 

Importation  of  all  forms  of  potash  salts.* 

Year.  Short  Tons.  Value. 

1900 :    358,736  $5,237,560 

1905 568,979  8,639,039 

1910 899,196  11,615.134 

1911 1,074,172  16,269,408 

This  table  is  compiled  from  Phalen— Potash  salts,  their  uses  and  occurence  in  the  United  States,  U.  S.  Geol.  Survey, 
advance  chapter  from  Mineral  Resources  for  1910;  and  from  Phalen— Potash  salts.  Summary  for  1911 ,  same,  1911. 


In  this  table  figures  for  calendar  year  and  fiscal  year  have 
been  added  together  without  distinction,  the  error  thus  intro- 
duced having  no  effect  on  the  general  meaning  of  the  table.  Of 
the  potash  imported  probably  three- fourths  or  more  goes  into  the 
manufacture  of  fertilizers,  and  it  is  this  use  that  is  so  greatly  in- 
creasing and  is  responsible  for  the  recent  rapid  rise  in  potash  im- 
ports. At  the  present  time  on  the  Atlantic  seaboard  crude  potas- 
sium nitrate  (niter)  is  worth  about  $65.00  per  short  ton,  potas- 
sium sulphate  about  $45.00,  and  potassium  chloride  (or 
"muriate")  about  $35.00.  There  is  every  prospect  that  these 
prices  will  rise  rather  than  fall. 


THE  GERMAN  POTASH  SALTS. 

Practically  all  the  potash  of  the  world  now  comes  from  the 
mines  at  Stassfurt,  Germany,  controlled  by  the  German  potash 
monopoly  or  Kali  Syndicate.  At  this  locality  various  soluble 
potash  salts  occur  in  solid  form  and  associated  with  large 
amounts  of  common  salt  and  gypsum  and  with  various  salts  of 
magnesium. 

The  potash  was  discovered  by  accident.  From  very  early 
times  brine  springs  and  wells  had  been  known  in  the  Stassfurt 
region,  and  common  salt  had  been  manufactured  there  for  cen- 
turies. About  1845  the  German  Government  undertook  to  in- 
crease the  supply  of  brine  for  common  salt  manufacture  by 
drilling  a  well  into  the  brine  bodies  supposed  to  lie  below.  This 
well  tapped  brines  carrying  such  large  quantities  of  potassium 
and  magnesium  salts  as  to  be  bitter  and  useless  for  salt  manu- 
facture. The  value  of  these  bitter  salts  in  themselves  was  not 
recognized  and  the  well  was  considered  a  failure.  A  few  years 
later  the  Government  sunk  a  shaft  which,  after  passing  through 
considerable  bodies  of  "bitter"  potash  and  magnesia  salts, 
reached  the  main  body  of  common  salt.  From  this  and  other 
similar  shafts  the  salt  was  extensively  mined,  the  potash  over- 
burden (then  believed  worthless)  being  removed  when  neces- 
sary and  thrown  away  as  waste  or  "abraumsalze."  This  contin- 
ued until  von  Liebig  suggested  the  possible  usefulness  of  this 
material  as  fertilizer.  About  1870  it  was  tried,  its  value  proven, 
and  the  wraste  heaps  of  the  mines  became  their  greatest  assets. 
At  the  present  time  the  potash  material  is  mined  by  deep  work- 
ings of  the  usual  type,  brought  to  the  surface  and  put  through 
such  chemical  or  mechanical  refining  as  may  be  necessary. 


The  potash  salts  are  seldom  pure,  but  are  associated  with 
various  compounds  of  sodium,  calcium  and  magnesium.  The 
deposit  contains  30  or  40  more  or  less  complex  minerals,  the 
more  important  of  which  are  the  following  : 

Sylvite  (or  sylvan),  chloride  of  potassium,  KC1. 

Carnallite,  a  hydrous  double  chloride  of  magnesium  and 
potassium,  KMgCls,  6H2O. 

Halite,  or  rock  salt,  chloride  of  sodium,  NaCl. 

Kainite,  a  combination  of  potassium  chloride  and  mag- 
nesium sulphate  with  3  molecules  of  water,  MgS(>4,  KC1,  3H2O. 

Polyhalite,  a  hydrous  triple  sulphate  of  calcium,  mag- 
nesium and  potassium,  2CaSC>4,  MgSO4,  K2SO4,  2H2O. 

Kieserite,  hydrous  magnesium  sulphate,  MgSO4,  H2O. 

Gypsum,  hydrous  sulphate  of  calcium,  CaSO4,  2HoO. 

Anhydrite,  anhydrous  sulphate  of  calcium,  CaSO4. 

Sylvanite  is  an  indefinite  mixture  of  sylvite  and  halite  (  rock 
salt)  .  "Hartsalz"  is  a  mixture  of  sylvite,  halite  and  kieserite. 

At  one  time  considerable  quantities  of  sylvite,  carnallite  and 
kainite  were  mined  directly  in  reasonably  pure  form,  but  this  is 
believed  not  to  be  now  the  case,  the  potash  salts  being  obtained 
in  a  variable  mixture  somewhat  lower  in  grade.  As  it  comes  to 
the  market  the  potash  is  mainly  in  four  forms  : 


1.  Sulphate  of  potassium,  KoSOi,  usually  containing  70  to 
90  per  cent  of  pure  potassium  sulphate. 

2.  Chloride   (or  "muriate")    of  potassium,  KC1,  usually 
containing  80  to  90  per  cent  of  pure  potassium  chloride.    Both 
sulphate  and  chloride  are  produced  by  the  more  or  less  complete 
refining  of  the  original  salts. 

3.  Kainite  (not  necessarily  the  same  as  the  mineral  kainite 
noted  above),  a  variable  mixture  of  the  mineral  kainite,  sylvite, 
halite,  kieserite,  etc.,  containing  12  to  15  per  cent  of  potash 
(KoO),  the  other  materials  being  chlorides  and  sulphates  of 
sodium  and  magnesium.    Kainite  usually  comes  to  the  market 
directly  from  the  mine  without  chemical  treatment. 

4.  "Manure  salts,"  a  similar  mixture,  usually  resulting 
from  partial  refining  and  divided  into  grades  containing  20,  30 
and  40  per  cent  potash  (KoQ). 


There  is  also  a  mine  classification  into  "carnallite  salts'* 
and  "kainite  salts/'  the  difference  being  that  the  former  consist 
essentially  of  carnellite,  the  latter  of  kainite  (mineral),  Hart- 
sal  (z  anil  sylvinite.  The  carnallite  salts  are  not  now  exported 
to  America. 


THE  GEOLOGY  OF  THE  STASSFURT  DEPOSITS. 


The  section  of  the  Stassfurt  deposits  is  somewhat  variable 
in  different  mines,  but  usually  includes  the  following  main 
divisions : 

1.  Drift,  shales,  sandstones,  etc.,  variable  thickness. 

2.  Younger  rock  salt,  variable  thickness. 

3.  Anhydrite,  100  to  250  feet  thick. 

4.  Salt  clay,  15  to  30  feet  thick. 

5.  Carnallite  zone,  consisting  of  carnallite,  halite,  kieser- 
ite,  etc.,  50  to  125  feet  thick. 

G.  Kieserite  zone,  consisting  of  rock  salt  with  kieserite  and 
kainite,  variable  thickness. 

7.  Polyhalite  zone,  consisting  of  rock  salt,  with  polyhalite 
and  other  magnesium  salts,  variable  thickness. 

8.  Older  rock  salt,  400  to  3000  feet  thick. 

9.  Anhydrite  and  gypsum. 

The  depth  of  the  potash-bearing  horizon  is  usually  800  to 
1000  feet.  The  various  divisions  are  seldom  sharply  separated 
from  each  other  and  some  are  occasionally  lacking.  In  partic- 
ular the  so-called  carnallite,  kieserite  and  polyhalite  zones  are 
sometimes  considerably  confused  and  divided  into  sub-zones  of 
variable  character.  The  lower  rock  salt  contains  many  thin 
(i/i-inch)  layers  of  anhydrite  alternating  with  slightly  thicker 
layers  of  rock  salt. 

According  to  the  theory  first  developed  by  Ochsenius  and 
now  generally  accepted,  the  Stassfurt  salts  resulted  from  the 
evaporation  of  a  large  body  of  sea  water  which  had  been  cut  off 
in  some  way  from  connection  with  the  ocean.  In  its  progressive 
concentration  this  sea  water  deposited  first  the  lower  gypsum 
and  anhydrite,  then  the  lower  or  "older"  rock  salt,  and  finally  its 
remaining  mother  liquors  or  "bitterns"  laid  down  the  mag- 
nesium and  potassium  salts  of  the  polyhalite,  kieserite  and  car- 


nallite  zones.  Following  this  some  geologic  change  caused  an 
inwash  of  clay,  which  formed  the  salty  clay  bed  noted  in  the 
section  and  sealed  the  previously  deposited  salts  against  subse- 
quent solution  and  removal.  A  new  body  of  sea  water  or  of 
brine  from  leaching  of  the  earlier  deposited  salt  seems  then  to 
have  been  supplied  and  concentrated,  thereby  producing  the 
upper  anhydrite  zone  and  the  upper  or  "younger"  rock  salt. 
Either  this  second  concentration  was  interrupted  before  it  had 
gone  far  enough  for  the  deposition  of  the  magnesium  and  potas- 
sium salts,  or  such  of  these  salts  as  were  deposited  were  removed 
by  subsequent  erosion.  At  the  present  time  the  later  deposited 
clays  and  shales  rest  directly  upon  the  younger  rock  salt. 

The  total  amount  of  potash  available  in  the  Stassfurt  de- 
posits is  unknown,  but  is  undoubtedly  very  large.  It  is  ru- 
mored, however,  that  the  high  grade  material  is  approaching 
exhaustion,  though  the  secrecy  which  surrounds  the  operations 
of  the  Kali  Syndicate  makes  it  impossible  to  verify  this  report. 
In  his  first  report  above  noted  Phalen  gives  figures  for  the  pro- 
duction of  the  German  mines  in  1908  as  7,372,144  short  tons, 
worth  $32,965,856.  No  later  figures  are  known  to  the  writer. 
Phalen  also  quotes  financial  figures  for  twenty-one  of  the  mines 
in  1906,  indicating  that  during  that  year  these  mines  earned  a 
total  of  |3,747,570  in  net  profits  on  a  total  capitalization  of 
.$23,502,625,  or  an  average  profit  of  15.9  per  cent. 

No  salt  deposit  similar  to  the  Stassfurt  body  is  known  else- 
where, and,  so  far  as  known,  none  of  the  other  rock  salt  bodies 
of  the  world  carries  significant  amounts  of  potash.  The  United 
States  Geological  Survey  and  the  United  States  Bureau  of  Soils 
have  devoted  some  effort  to  a  study  of  brines  from  the  various 
North  American  salt  bodies,*  but  no  indications  of  potash  have 
been  discovered.  It  is  not  impossible  that  a  potash  deposit  of  es- 
sentially the  Stassfurt  type  may  exist  somewhere  in  the  United 
States  or  in  the  world,  but  the  writer  is  acquainted  with  no  cri- 
teria by  which  its  presence  or  location  could  be  inferred  in  ad- 
vance of  discovery. 

THE  AMEEICAN  POTASH  SEAKCH. 

The  recent  rapid  increase  in  the  consumption  of  potash  in 
the  United  States  and  the  absolute  dependence  of  this  country 
upon  the  German  supply  have  stimulated  both  private  and  Gov- 
ernmental agencies  to  a  very  active  search  for  American  de- 

*A  preliminary  report  has  been  published  by  Phalen,— U.  S.  Geological  Survey,  Bulletin  530B  (1911). 


posits  or  sources.  As  a  result  there  have  been  many  suggestions 
not  only  of  favorable  localities  for  prospecting  but  of  materials 
known  to  be  available  and  from  which  potash  might  be  ex- 
tracted. For  instance,  a  considerable  proportion  of  potash  is 
contained  in  orthoelase  feldspar,  and  many  processes  have  been 
suggested  for  its  extraction  and  utilization.  Leucite,  muscovite 
and  other  silicate  minerals  also  contain  significant  quantities  of 
potash,  and  alunite,  a  basic  sulphate  of  potassium  and  alum- 
inum, has  actually  been  used  as  a  source  of  potash  alum.  So 
far,  none  of  these  minerals  looks  very  promising  as  a  commer- 
cial source  of  potash.  To  have  fertilizing  value  it  seems  neces- 
sary that  the  potash  be  added  to  the  soil  in  soluble  form.  It 
does  little  or  no  good  to  use  the  potash  silicates  directly  on  the 
soil,  and  as  yet  no  practicable  process  has  been  developed  for 
the  preparation  of  soluble  potash  salts  from  them.  Alunite, 
though  it  yields  soluble  potash  more  easily,  is  not  known  in  the 
United  States  except  in  small  deposits  or  as  a  comparatively 
minor  constituent  of  certain  rocks. 

Perhaps  a  little  greater  promise  is  offered  by  the  kelps  or 
giant  sea  weeds  of  the  Pacific  Coast.  These  carry  considerable 
amounts  of  potash  salts — amounting  to  3  to  5  per  cent  of  the 
wet  material — and  the  nitrogenous  substances  which  make  up 
nearly  all  the  remaining  solids  are  also  very  beneficial  to  the 
soil.  There  is  little  question  of  the  quantity  of  kelp  available 
or  of  its  considerable  value  as  a  fertilizer,  but  some  very  difficult 
problems  of  gathering  and  drying  stand  in  the  way  of  its  com- 
mercial utilization.  It  is  quite  possible  that  these  problems 
will  be  solved,  as  it  is  quite  possible  that  methods  will  be  de- 
vised for  the  extraction  of  potash  from  silicate  minerals,  but 
potash  from  either  source  will  probably  have  to  carry  a  consid- 
erable cost  of  production  and  will  compete  with  difficulty  with 
potash  directly  obtained  in  soluble  form.  Both  kelp  and  sili- 
cates constitute  large  potential  sources  of  potash  and  form  a 
reserve  upon  which  we  can  confidently  expect  to  be  able  to  draw 
if  all  other  supplies  should  fail. 

It  is,  however,  the  judgment  of  the  present  writer  that  the 
only  hope  of  immediate  competition  against  the  German  supply 
lies  in  the  discovery,  of  American  deposits  of  the  soluble  salts. 
Mention  has  already  been  made  of  the  lack  of  indication  of  other 
deposits  of  the  Stassfurt  type,  and  it  seems  that  the  best  and 
almost  the  only  chance  of  developing  immediately  available 
American  sources  lies  in  the  basins  or  "dry  lakes"  of  the  Great 
Basin  and  other  arid  regions. 

10 


THE  "DRY  LAKE'7  POTASH  THEORY. 

By  the  natural  processes  of  weathering  all  rocks  and  min- 
erals give  up  certain  of  their  constituents  in  the  form  of  soluble 
salts  of  sodium,  potassium  and  other  elements.  These  salts  are 
dissolved  by  rain  and  ground  water  and  pass  into  the  streams. 
All  natural  waters  contain  in  solution  more  or  less  material 
thus  derived  and  hence  tend  to  correspond  in  chemical  character 
to  the  rocks  of  the  country,  from  which  they  drain.  The  high 
lime  content  of  limestone  waters  is  a  well-known  example. 

In  ordinary  regions  the  salts  of  the  drainage  waters  are 
carried  from  stream  to  river  and  finally  to  the  sea.  Indeed, 
geologists  are  agreed  that  the  salinity  of  ocean  water  has  been 
thus  acquired.  There  are,  however,  regions  from  which  the 
drainage  has  no  seaward  egress,  but  concentrates  in  a  lake  or 
"sink"  and  then  suffers  evaporation.  In  such  cases  the  salts  de- 
rived from  rock  decay  are  locally  accumulated  where  the  waters 
evaporate,  and  form  either  a  bed  of  salt,  as  in  Death  Valley,  or 
the  salinity  of  a  bottom  lake  like,  for  instance,  the  Great  Salt 
Lake  of  Utah. 

Now  nearly  all  rocks  and  soils  contain  some  potash-bearing 
minerals,  and  these,  on  weathering,  set  free  soluble  salts  of  pot- 
ash. It  follows,  therefore,  that  all  normal  drainage  waters  con- 
tain more  or  less  of  these  potash  salts.  Ordinarily,  however,  the 
potash  is  in  small  amounts  and  is  far  surpassed  by  the  quanti- 
ties of  sodium  salts  present.  In  normal  waters  the  potassium 
salts  vary  between  1  per  cent  and  4  per  cent  of  the  total  dis- 
solved materials.  Only  very  rarely  do  they  exceed  the  lat- 
ter value.  Even  4  per  cent  of  potash  in  a  salt  body  is 
ordinarily  far  too  low  to  be  commercially  utilizable,  and  if  a 
valuable  potash  body  is  to  be  formed  there  must  be  not  only  salt 
accumulation  by  the  concentration  of  enclosed  drainage  waters, 
but  also  some  sort  of  natural  segregation  of  the  potash  from  at 
least  a  part  of  the  other  salts  which  are  present. 

Whether  a  workable  potash  deposit  can  have  been  formed  by 
the  concentration  of  drainage  in  enclosed  basins  depends  upon 
two  considerations :  ( 1 )  Are  there  any  places  where  the  evap- 
oration of  natural  drainage  waters  has  accumulated  potash  in 
sufficiently  large  amounts?  (2)  Has  there  been  possible  in  any 
of  these  places  a  sufficiently  complete  segregation  of  the  potash 
from  the  much  larger  amounts  of  sodium  salts  which  must  have 


accumulated  with  it?  The  first  of  these  questions  can  be  an- 
swered at  once  in  the  affirmative.  There  are  a  number  of  en- 
closed basins  in  North  America,  where  very  large  amounts  of 
drainage  water  have  evaporated  for  very  long  times,  and  for 
many  of  these  basins  there  is  ample  evidence  that  the  drainage 
waters  were  normal  or  above  normal  in  their  content  of  potash. 
The  question  of  possible  segregation  of  the  potash  is  less  cer- 
tain and  its  consideration  must  be  prefaced  by  a  brief  discus- 
sion of  the  recent  geologic  history  of  the  regions  of  present  en- 
closed drainage. 

This  historical  discussion  need  not  be  complete.  It  is  suf- 
ficient to  note  that  at  a  time  geologically  recent  though  his- 
torically remote  the  deepest  depressions  of  many  of  the  enclosed 
basins  of  North  America  were  filled  with  great  lakes.  This  lake 
period  is  generally  regarded  as  synchronous  with  the  Glacial 
Period  and  is  due  to  similar  climatic  causes — an  increase  of 
rainfall  or  a  lowering  of  mean  temperature,  or  both.  The  lakes 
which  characterized  this  period  have  disappeared  or  shrunk  to 
tiny  remnants,  but  their  previous  size  and  persistence  is  attested 
by  innumerable  sand  bars,  wave-cut  terraces  and  similar  topo- 
graphic records  which  it  is  impossible  to  mistake.  The  lakes 
seem  to  have  been  characterized  by  frequent  and  extreme  fluc- 
tuations of  level,  and  there  is  good  evidence  that  the  lake  period 
was  at  least  double,  two  periods  of  expansion  being  separated  by 
a  period  of  contraction  and  desiccation,  probably  to  entire  dry- 
ness.  The  second  expansion  was  followed  by  contraction  to  the 
present  condition  of  desiccation. 

A  number  of  these  ancient  lakes  overflowed  at  their  great- 
est expansion,  and  most  of  the  salts  which  they  contained  es- 
caped to  the  sea.  Others,  however,  never  attained  an  overflow 
and  must  have  retained  all  salts  derived  from  their  drainage 
basins.  At  their  higher  stages  the  lakes  must  all  have  been 
fresh,  but  as  they  began  to  evaporate  and  contract  they  must 
have  become  increasingly  brackish  and  finally  more  and  more 
saline,  paralleling  the  present  condition  of  the  Great  Salt  Lake 
of  Utah  and  of  Owens  and  Mono  Lakes  in  California.  This  may 
have  furnished  an  opportunity  for  the  segregation  of  the  potash. 
It  is  reasonably  certain  that  some,  at  least,  of  the  lakes  con- 
tained normal  proportions  of  this  material.  Potash  salts  are 
more  soluble  than  those  of  sodium.  It  is  probable,  therefore, 
that  when  the  concentrating,  potash-containing  lakes  came 
finally  to  the  point  of  precipitating  their  dissolved  salts,  the 
sodium  and  calcium  salts  would  be  the  first  to  go,  and  the  salts 

12 


of  potassium  would  be  retained  and  concentrated  in  the  mother 
liquors.  Finally,  when  these  mother  liquors  came  to  be  evap- 
orated they  would  deposit  a  body  of  salts  relatively  high  in  pot- 
ash. Essentially  this  is  just  what  is  supposed  to  have  happened 
in  the  Stassfurt  concentration  above  described,  though  there  the 
original  water  was  that  of  the  sea.  The  sodium  chloride  was 
thrown  out  first  as  rock  salt  and  the  more  soluble  magnesium 
and  potassium  salts  came  down  later  in  fairly  concentrated 
form. 

Were  it  certain  that  the  ancient  lakes  had  undergone  their 
concentration  continuously  and  uniformly,  there  would  be  lit- 
tle question  of  this  theory.  Unfortunately,  however,  this  is  far 
from  being  the  case.  There  is  good  evidence  that  the  lakes  were 
subject  to  many  fluctuations  both  up  and  down.  Their  evap- 
oration, instead  of  being  a  slow  and  steady  downward  move- 
ment, was  almost  certainly  a  series  of  relatively  sudden  expan- 
sions and  contractions,  relieved  by  considerable  periods  of 
nearly  constant  level,  and  having  a  general  net  tendency  toward 
contraction.  This  detailed  history  is  so  complex  and  so  little 
known  that  its  effect  on  the  segregation  of  the  potash  can 
scarcely  be  predicted.  It  is  conceivable,  though  scarcely  prob- 
able, that  the  continual  and  wide  fluctuations  of  the  lakes  may 
have  prevented  any  important  segregation  of  their  contained 
salts. 

In  summary  this  theory  reduces  to  rather  simple  terms : 

1.  In  certain  enclosed  basins  of  North  America  (now  dry) 
there  were  once  great  lakes,  some  of  which  never  possessed  an 
outlet. 

2.  These  lakes  must  have  come  to  contain  large  amounts 
of  salts,  and,  in  some  cases  at  least,  these  salts  must  have  in- 
cluded large  total  amounts  and  not  insignificant  proportions  of 
potash. 

3.  On  the  evaporation  of  these  lakes  their  salts  must  have 
been  deposited  in  their  basins  and  it  is  possible  that  natural 
piocesses  may  have  produced  a  more  or  less  complete  segrega- 
tion of  the  potash  from  the  other  saline  materials. 

When  we  come  to  test  this  theory  by  application  to  the  ac- 
tual salt  deposits  of  the  desert  basins,  we  are  immediately  con- 
fronted by  the  fact  that  the  floors  of  the  desert  valleys  are  sel- 
dom especially  saline.  The  writer  knows  only  three  or  four 

13 


American  basins  Avhere  (lie  salt  deposits  visible  on  the  floor 
rould  account  for  more  than  a  small  fraction  of  the  salt  that 
must  have  been  present  in  the  lake  which  the  basin  once  con- 
l allied.  This  surprising  fact  became  patent  very  early  in  the 
investigation  of  the  desert  basin  regions,  and  Gilbert  and  Rus- 
sell, who  Avere  the  scientific  pioneers  in  this  field,  developed  in 
explanation  the  theory  of  "freshening  by  desiccation."  Accord- 
ing to  this  theory,  the  salt  body  formed  by  the  complete  desicca- 
tion of  a  lake  might  be  gradually  covered  by  clay  or  sand  washed 
or  blown  in  from  its  surroundings,  and  thus  protected  against 
solution  even  though  later  covered  by  another  persistent  lake. 
There  seems  little  question  of  the  reality  of  this  process.  It  has 
actually  been  observed  taking  place  at  present,  and  a  similar 
phenomenon  in  the  Stassfurt  deposits  was  noted  above.  There 
is  every  reason  to  believe  that  the  present  non-saline  floors  of 
the  old  lake  basins  conceal  somewhere  beneath  them  the  miss- 
ing salts  of  the  early  lakes. 

But  this  theory  itself  suggests  another  process  which  may 
possibly  have  interfered  with  segregation  of  potash.  If  alluvium 
has  been  added  since  the  complete  evaporation  of  the  lakes,  it 
was  doubtless  added  in  even  greater  quantity  during  that  evap- 
oration, and  it  is  not  impossible  that  this,  joined  to  the  irregular 
fluctuations  of  the  lakes,  may  have  caused  the  salts  (including 
the  potash)  to  have  been  deposited  with  the  added  alluvium  as 
saline  clay  beds,  rather  than  as  beds  of  actual  salt.  How  far 
this  suggestion  may  have  had  reality  is  absolutely  unknown. 

The  above  theory,  though  entirely  general,  rests  on  much 
that  is  concrete  and  specific,  and  may  fairly  be  said  to  lead  to 
the  conclusion  that  segregated  potash  deposits  may  have  been 
formed  in  some  of  the  undrained  basins.  Thus  stated,  the  the- 
ory has  received  ample  vindication  from  the  actual  discovery 
of  such  a  segregated  potash  deposit  at  Searles  Lake,  San  Ber- 
nardino County,  California.  At  this  place  the  potash  is  con- 
tained in  a  brine  or  mother  liquor  which  permeates  the  mass  of 
a  considerable  body  of  crystalline  salts  of  sodium.  Progressive 
evaporation  has  thrown  out  a  large  part  of  these  other  salts 
from  the  original  solution,  leaving  the  potash  segregated  in  the 
mother  liquor.  The  general  theory  is  borne  out  in  every  way. 
It  is  true  that  the  Searles  Lake  salt  body  is  at  the  surface  in- 
stead of  buried,  but  the  surroundings  of  the  deposit  are  such  as 
to  greatly  strengthen  rather  than  weaken  the  general  theory  of 
burial  of  salt  beds.  Not  only  is  the  failure  of  the  Searles  Lake 
deposit  to  have  become  entirely  covered  easily  explainable  by  a 

14 


local  and  unusual  topography,  but  the  process  of  covering  has 
actually  been  at  work.  The  edges  of  the  salt  body  are  already 
covered  by  encroaching  alluvium  and  a  few  hundred  more  years 
of  the  present  conditions  would  doubtless  have  covered  the  de- 
posit entirely.  As  a  whole,  the  Searles  deposit  offers  nothing 
to  weaken  the  general  theory  and  much  to  support  it. 

It  does  not  necessarily  follow  that  other  similar  deposits 
exist.  It  is  perhaps  justifiable  to  say  that  Searles  sufficiently 
confirms  the  general  theory,  but  the  general  theory  may  be  per- 
fectly sound  and  yet  may  have  failed  of  exact  and  complete 
realization  elsewhere.  The  chances  of  the  occurrence  of  a  pot- 
ash body  in  any  particular  basin  are  matters  determinable,  if 
at  all,  only  by  the  local  and  particular  character  and  history 
of  the  basin.  Probably  the  criteria  applicable,  and  the  general 
chances,  favorable  and  unfavorable,  will  sufficiently  appear  in 
the  following  discussion  of  the  Railroad  Valley. 

The  Railroad  Valley  is  an  enclosed  basin  lying  just  south- 
east of  the  geographical  center  of  Nevada.  Several  adjoining- 
valleys  are  and  have  been  tributary  to  it,  and  its  drainage  area 
during  the  great  lake  period  was  about  6400  square  miles.  Some 
of  the  former  tributaries  have  been  cut  off  by  dams  of  recent 
alluvium  or  by  the  desiccation  of  the  streams  wrhich  once 
drained  them,  but  these  changes  are  recent  and  unimportant. 
The  passes  leading  out  of  the  drainage  basin  are  all  ancient  and 
fairly  high  and  there  is  no  doubt  that  the  basin  has  been  for  a 
long  time  an  enclosed  one  and  has  never  overflowed.  A  series 
of  old  wave  bars,  beaches,  etc.,  surround  the  valley  and  indicate 
the  existence  of  an  ancient  lake  which  seems  to  have  had  the 
usual  history.  The  exposed  rocks  and  soils  of  the  valley  carry 
rather  more  than  the  normal  proportion  of  potash-bearing  min- 
erals and  there  is  every  reason  to  believe  that  the  early  Railroad 
Valley  Lake  had  its  full  share  of  potash  and  that  that  potash  is 
now  within  the  valley.  The  questions  are  two:  (1)  Was  the 
potash  segregated?  (2)  Can  it  be  located? 

Investigations  to  date  have  not  sufficed  for  the  definite  an- 
swering of  either  of  these  questions.  The  present  surface  of  the 
valley  contains  no  large  salt  body.  The  deepest  depression  is  a 
mud  flat  or  "playa,"  very  nearly  level  and  not  particularly 
saline.  About  its  borders,  at  both  north  and  south  ends,  are  a 
number  of  smaller  mud  flats  or  "pans,"  which  are  much  more 
saline  and  in  which  the  superficial  ground  waters  are  usually 
concentrated  brines.  These  brines,  rising  to  the  surface  by  cap- 

15 


illarity,  evaporate  to  produce  thin  surface  crusts  of  white  salt. 
The  salts  of  both  brines  and  crusts  frequently  carry  5  to  12  per 
cent  of  potash,  but  the  quantity  of  the  brine  is  not  believed  to  be 
large  and  it  seems  to  occur  in  separate  local  pockets,  showing 
considerable  chemical  differences.  Both  the  origin  and  the 
n  mount  of  these  surface  brines  well  deserve  the  investigation 
which  they  are  now  receiving  on  the  ground,  but  it  is  the  pro- 
visional opinion  of  the  writer  that  the  material  will  prove  small 
in  quantity  and  not  particularly  important.  The  interest  of 
these  superficial  high-potash  brines  to  the  present  prospecting  in 
the  valley  is  two-fold — they  first  directed  attention  to  the  valley 
as  a  possible  potash  locality  and  they  indicate  that  potash  ac- 
cumulation and  segregation,  on  a  small  scale  at  least,  has  actu- 
ally occurred  in  the  basin. 

It  is  not  believed  that  the  amount  of  salt  contained  in  these 
surface  brines  is  nearly  large  enough  to  account  for  the  salt 
which  must  have  been  in  the  early  lake.  The  theory  of  burial 
seems  to  apply  in  every  detail  and  there  is  every  reason  to  be- 
lieve that  large  quantities  of  salts  are  buried  somewhere  in  the 
basin  and  that  these  salts  contain  a  significant  proportion  of 
potash. 

As  to  the  possible  segregation  of  the  potash  from  the  other 
salts,  there  is  no  specific  data,  and  opinion  must  rest  upon  the 
general  theoretical  considerations  above  discussed.  These  the- 
oretical considerations  do  not  warrant  any  final  conclusion  for 
or  against  the  segregation  of  the  potash,  but  they  indicate  that 
such  a  segregation  is  quite  possible.  In  the  opinion  of  the  writer 
the  chances  of  such  a  segregation  having  occurred  are  ample  to 
warrant  an  attempt  to  locate  the  hypothetical  buried  salt  bed  in 
the  hope  that  this  bed  may  contain  one  or  more  horizons  of  use- 
ful potash  material.  Of  course,  it  is  quite  possible  that  the  pot- 
ash may  not  have  been  sufficiently  separated  from  other  salts,  or 
that  both  potash  and  other  salts  were  deposited  with  alluvium  in 
the  form  of  saline  clays.  These  are  uncertainties  which  cannot 
be  removed  except  by  actual  investigation. 

The  location  of  the  hypothetical  buried  bed  is  not  a  matter 
of  extreme  ease.  Th,e  inwash  of  recent  alluvium,  the  movement 
of  dune  sand,  etc.,  have  considerably  changed  the  minor  topog- 
raphy of  the  basin.  It  is  quite  possible  that  the  point  of  deepest 
depression  has  been  shifted  by  these  agencies,  and  that  the  place 
which  was  deepest  at  the  time  of  the  original  lake  concentration, 

• 

16 


and  which  contains  the  hypothetical  salt  bed  is  not  now  directly 
under  the  present  mud  flat.  It  is  not  possible,  therefore,  to  so 
locate  a  single  drill  hole  that  it  would  be  certain  to  find  the  salt 
bed  if  it  exists.  Any  hole,  located  without  knowledge  of  under- 
ground conditions  and  of  the  ancient  topography,  might  easily 
miss  the  edge  of  the  saline  beds  and  fail  to  show  their  existence. 
Indeed,  a  number  of  holes  might  have  to  be  drilled  before  the 
bed  was  located  or  its  existence  disproved.  It  is  the  opinion  of 
the  writer  that  a  maximum  of  four  holes  would  probably  be  suf- 
ficient. It  is  probable  that  the  records  of  lake  expansion  and 
desiccation  can  be  identified  even  in  holes  which  miss  the  central 
salt  body,  and  the  comparative  study  of  such  records  from  three 
properly  placed  holes  would  make  possible  the  reconstruction  of 
the  ancient  topography  of  the  basin  with  sufficient  accuracy  to 
enable  the  placing  of  the  fourth  hole  where  its  record  would  be 
conclusive.  Good  fortune  might  make  the  first  or  the  second 
or  the  third  hole  conclusive,  but  this  really  could  not  be  ex- 
pected. 

There  is  also  no  complete  assurance  that  a  hole  could  be 
drilled  deep  enough  to  reach  the  saline  beds.  The  Railroad  Val- 
ley, like  most  of  the  .enclosed  basins,  is  filled  with  alluvial  mate- 
rial to  a  very  great  depth — probably  many  thousands  of  feet. 
Undoubtedly  much  of  this  filling  antedates  the  lake  period  and 
does  not  concern  us,  but  there  is  absolutely  no  way  of  knowing 
how  much  later  alluvium  may  have  been  deposited  or  how  deeply 
the  significant  beds  have  been  buried.  The  writer  knows  of  no 
well  record  in  any  basin  sufficiently  complete,  accurate  and  deep 
to  enable  the  identification  of  the  horizon  of  the  early  lake. 
There  is,  tlierfore,  no  scale  by  which  can  be  measured  the  amount 
of  alluvial  deposition  subsequent  to  the  lake  period. 

As  a  matter  of  fact,  the  depth  of  the  saline  "desiccation 
beds' '  will  probably  prove  to  be  widely  different  in  different 
basins,  the  depth  in  any  particular  basin  depending  upon  the 
local  topographic  conditions  which  have  controlled  the  supply 
of  alluvium.  It  is  the  opinion  of  the  writer  that  the  alluvial 
fill  in  the  Railroad  Valley  is  comparatively  shallow  and  that  the 
critical  strata  will  be  encountered  inside  of  1500  feet  or  only 
slightly  below  that  level.  This  opinion,  however,  is  admittedly 
little  better  than  a  guess,  and  is  entirely  unsupported  by  any 
direct  evidence. 

However,  evidence  on  this  point  is  being  rapidly  acquired. 
The  drill  hole  being  sunk  by  the  Railroad  Valley  Company  is 

17 


now  nearly  1200  feet  deep  and  is  going  down  rapidly.  A  full 
and  careful  record  has  been  kept  and  a  very  complete  series  of 
samples  has  been  preserved.  The  record  of  the  hole  to  August 
19,  1912,  is  given  in  the  following  table: 


LOG  OF  EAILROAD  VALLEY  HOLE. 


Feet. 

1-32  Sand  with  occasional  clay  lay- 

ers. 

32-103  Quicksand. 

103-132         Alternations  of  quicksand 
and  clay. 

132-136  White  clay  with  small  seams 
of  fine  gravel  or  coarse 
quicksand. 

136-178         Heavy  clay. 
178-214        Quicksand. 

214-285  Alternations  of  clay  and  sand, 
layers  1  ft.  to  io  ft.  thick. 


285-305  Sand,  coarser  in  upper  part. 
Pebbles  3-4  in.  in  dia.  at 
285  ft. 

305-336         Tough  clay. 

336-340  Quicksand  with  some  clay  and 
some  small  gravel. 

340-365  Clay,  with  occasional  streaks 
of  quicksand. 

365-375  Quicksand  with  very  small 
streaks  of  clay. 

375-390         Tough  gray  clay. 
390-391         Quicksand. 
391-418         Tough  gray  clay. 


Artesian  water,  es- 
pecially at  128  ft. 


Artesian  water. 

Artesian    water   in 
most  of  the 
sands,  especially 
at  220  and  250  ft. 


Artesian  water. 
Artesian  water. 

Artesian  water. 
Small  artesian  flow. 


18 


418-419         Quicksand. 
419-429         Brown  clay. 
429-430         Quicksand. 

430-460  Clay,  gray  in  lower  part, 
changing  to  brown  in  up- 
per. 

460-461         Quicksand. 

462-470  Blue-green  clay,  with  a  white 
layer  on  top. 

470-471  Quicksand. 

471-478  Lead-colored  clay. 

478-479  Very  fine  sand. 

479-500  White  and  blue-green  clays. 

500-504  Blue-green  clay  with  some 
coarse  sand. 

504-519        White  and  blue-green  clays. 
519-520         Quicksand. 


519-529         Gray    clay    with     occasional 
sand  streaks. 


529-533        Gray  clay. 

533-534         Very  fine  quicksand. 

534-539         Blue-green  clay. 

539-541  Quicksand  with  some  light 
colored  clay  and  some 
coarse  gravel. 

541-560  Yellowish,  white  and  blue- 
green  clays. 

560-561         Quicksand. 

561-586         Blue-green  and  white  clays. 


Small  artesian  flow. 
Small  artesian  flow. 

Artesian  water. 
Artesian  water. 


Artesian  flow  smell- 
ing of  sulphur- 
etted hydrogen. 

Small  artesian 
flows  in  sands. 
All  smell  of  sul- 
phuretted hydro- 
gen. 


Strong  artesian 
flow. 


Artesian  water. 


19 


r»S6-r>S<         Quicksand. 

5S7-596        Clay. 

."W6-609  Alternations  of  sand  and  Hay, 
the  proportion  of  sand  in- 
creasing downward. 

609-637         Clay,  whiter  in  upper  part. 
637-638        Quicksand. 

038-676  Tough  clay,  white  and  green- 
ish in  color. 

676-677         Quicksand. 

677-680  Alternations  of  clay  and  sand. 

680-691  White  clay. 

691-700  Alternations  of  clay  and  sand. 

700-719  Clay,  brownish  on  top. 

719-720  Sand. 

720-738  Brownish  clay. 

738-746  Clay  and  quicksand  mixed. 
Some  coarse  gravel. 

746-759         Tough  brownish  clay. 

759-771  Sand  alternating  with  very 
tough  brownish  clay. 

771-785  Tough  brownish  clay. 

785-786  Quicksand. 

786-790  Clay. 

790-791  Sandy  streak  in  clay. 

791-798         Brownish  clay. 

798-805        Alternations  of  clay  and  sand. 

805-816  Clay,  hard  and  brown  in 
lower  part. 


Small  artesian 
flow. 


Small  artesian 
flow  at  605  ft. 


Small  artesian 
flow. 


Very  small  artesian 
flows. 


Very  small  artesian 
flows  in  the 
sands. 


Artesian  flow. 


Small  artesian 
flow. 


20 


816-822         Quicksand  and  gravel. 
822-824         Hard  white  clay. 

824-846  Clay  and  sand  alternating 
every  2  to  6  inches.  Pro- 
portion of  clay  increases 
with  depth. 

846-850        Brownish  clay. 
850-855         Sand  and  gravel. 

855-865  Rapid  alternations  of  clay 
and  sand. 

865-876  Gray  clay. 

876-878  Coarse  gravel. 

878-882  Fine  sand. 

882-899  Alternations  of  clay  and  sand. 

899-908  Gray  clay. 

908-924  Sand  and  gravel. 

924-934  Light  gray  clay. 

934-941  Fine  sand. 

941-945  Gray  clay. 

945-947  Sand. 

947-967  Clay,  yellow  on  top,  gray  be- 
low. 

967-968         Sand  and  gravel. 

968-1088       Hard,  dry  clay. 
1088-1089     Dry  sand. 
1089-1175     Hard,  dry  clay. 


Artesian  water. 


Strong  artesian 
flows  in  all  sand 
strata. 


Artesian  water 


Strong   artesian 
flows. 


Small  artesian 
flow. 


This  record  falls  without  violence  into  five  main  divisions : 

I.  1-103  feet — Sand  with  thin  layers  of  clay. 
II.  104-375  feet — Alternate  sand  and  clav. 


21 


III.  375-5W>    feet — riay   with   occasional   thin   streaks   of 
sand. 

IV.  .V.M5-JMJS  IVet — Alternate  sand   and   clay. 
V.  968-1175  feet— Solid  clay. 

In  the  interpretation  of  records  of  this  character  certain 
general  principles  are  of  service.  Solid  clay  beds  mean  perma- 
nent lake  conditions  over  the  site  of  the  drill  hole.  Alternations 
of  sand  and  clay  usually  mean  the  recurring  expansion  and  con- 
traction of  a  shallow  lake,  the  sand  layers  being  produced  by 
stream  wash  or  dune  movement  when  the  site  was  outside  the 
lake  or  at  its  shore,  while  the  clay  layers  indicate  periods  when 
the  lake  advanced  and  covered  the  site  for  a  longer  or  shorter 
time.  Sand  unmixed  with  clay  probably  indicates  conditions 
of  intense  aridity,  complete  desiccation,  and  extensive  move- 
ment of  dune  sand.  Applying  these  principles  to  the  record  as 
given  in  the  condensed  table,  it  is  apparent  that  division  I  prob- 
ably corresponds  to  a  period  of  intense  aridity  and  dune  move- 
ment in  the  recent  past.  The  reality  of  such  a  period  is  indi- 
cated by  much  evidence  from  other  regions,  and  may  be  consid- 
ered fairly  well  established.  Divisions  II  and  IV  obviously 
correspond  to  intermittent  lake  conditions,  and  division  V  to  a 
persistent  lake,  the  deposits  of  which  are  not  yet  bored  through. 
The  interpretation  of  division  III  is  less  certain.  Over  95  per 
cent  of  this  division  is  clay,  yet  the  recurrence  of  thin  sand 
streaks  seems  to  negative  the  existence  of  a  permanent  lake. 
The  writer  is  inclined  to  interpret  it  as  the  record  of  a  fairly 
permanent  but  shallow  lake,  the  shore  line  of  Avhich  stood  not 
far  from  the  site  of  the  drill  hole — close  enough  that  sand  could 
occasionally  be  washed  outward  to  cover  the  site. 

In  its  influence  on  the  potash  theories  two  interpretations 
of  this  record  are  possible.  It  will  be  recalled  that  the  early 
lake  period  was  apparently  double,  a  first  and  a  second  expan- 
sion being  separated  by  a  period  of  contraction.  Applying  this 
to  the  well  record,  it  is  possible  either  to  correlate  division  III 
of  the  condensed  record  with  the  second  lake  expansion  and 
division  V  with  the  first,  or  to  correlate  division  V  with  the  sec- 
ond expansion,  assuming  that  the  record  of  the  first  expansion 
is  still  below,  and  that  divisions  I  to  IV  correspond  to  minor 
fluctuations  subsequent  to  the  second  expansion.  The  writer 
has  not  personally  examined  the  samples  from  below  916  feet, 
and  before  doing  so  he  cannot  express  a  final  opinion  as  to 
which  of  these  alternative  correlations  is  correct,  He  inclines, 

22 


however,  to  the  second,  not  only  because  division  III  is  scarcely 
a  typical  record  of  persistent  lake  conditions,  but  because  di- 
vision IV  when  examined  in  detail  shows  no  indication  of  the 
long  and  intense  arid  period  which  is  believed  to  have  inter- 
vened between  the  tAvo  lake  expansions. 

There  is  reason  to  believe  that  the  second  lake  expansion 
was  considerably  shorter  than  the  first,  and  this  has  two  conse- 
quences: (1)  The  clay  beds  corresponding  to  this  lake  will  be 
relatively  thin,  and  (2)  the  greater  salt  body  will  have  been 
produced  by  the  concentration  of  the  first  lake  and  wrill  be  under 
these  clay  beds.  If  all  this  is  right,  and  if  the  writer  is  correct 
in  his  very  tentative  interpretation  of  the  well  record,  saline 
waters  are  to  be  expected  in  the  well  so  soon  as  the  clay  beds  now 
being  traversed  by  the  drill  have  been  penetrated.  It  is  to  be 
expected,  further,  that  these  clay  beds  will  not  be  too  thick  for 
their  penetration  to  be  possible.  On  this  interpretation  the  salt 
accumulated  during  the  second  lake  expansion  is  represented 
by  that  now  found  in  the  surface  and  sub-surface  beds  of  the 
mud  flat,  there  being  very  probably  areas  of  local  accumula- 
tion, not  deeply  buried  but  unknown,  and  not  cut  by  the  pres- 
ent drill  hole. 

Of  course,  this  interpretation  of  the  record  is  very  uncer- 
tain and  provisional  and  the  writer  does  not  feel  willing  to  haz- 
ard any  definite  predictions.  He  would  not  be  surprised,  IIOAV- 
ever,  to  see  saline  beds  or  saline  artesian  brines  encountered 
not  very  far  below  the  heavy  clay  beds  in  which  the  drill  is  now 
working.  Whether  these  saline  materials,  if  found,  will  con- 
tain workable  quantities  of  potash  remains,  as  before,  an  open 
question. 

In  summary,  all  information  so  far  obtained,  though  not  at 
all  conclusive,  tends  to  confirm  the  general  theory  outlined 
above.  A  commercially  valuable  potash  deposit  in  the  Kailroad 
Valley  is  distinctly  possible.  If  it  fails  to  be  found,  it  will 
almost  certainly  be  because  of  one  or  more  of  the  following- 
reasons  : 

1.  The  general  theory  may  be  wrong  in  some  essential  de- 
tail, the  error  having  remained  undetected. 

2.  The  hypothetical  salt  body  may    be  too    deep    to    be 
reached. 

23 


3.  The  potash  associated  with  it  may  have  failed  to  segre- 
gate sufficiently  to  be  of  value. 

E.  E.  FllEE. 

Sail   Fnmrisco,  Tal.,  August  ±j, 


